After being treated to full-throttle performances of Ludwig van Beethoven's Ninth Symphony and his late string quartets, you may walk out of "Copying Beethoven" humming the movie. But that's not the same as singing its praises.

A sort of mock biopic -- a cousin to the popular "mockumentary" -- it pairs Ludwig (Ed Harris, sporting a mop of unruly hair and a prosthetic nose) in the final phase of his career with a fantasy young assistant, Anna Holtz (Diane Kruger), hired to copy his hastily scribbled scores onto sheet music that would be legible to musicians. Anna serves as the maestro's sounding board, allowing him to vent his frustration at his deafness and to expound on how he recognizes when he's composed something great even without hearing it.

That's an intriguing idea, offering an opportunity usually available only to scientific researchers to pry inside the brain of a genius. The filmmakers should have stuck with it instead of continually shifting the focus onto the extremely boring Anna. If they had, they might have come up with a movie worthy of the enormous energy and raw nerve Harris throws into his thrilling performance.

Following "Pollock" and "The Hours," "Copying Beethoven" completes his trilogy of tortured virtuosos. None of his acting peers come close to copying his pained expressions. Deftly directed by Agnieszka Holland ("Europa, Europa"), Harris brings much more to Ludwig -- a sense of the joy of creation and an incontrovertible belief in himself.

His certainty in his instincts to be able to distinguish between true talent and the banal often leads to boorish behavior. Harris is quite amusing in a scene where Ludwig makes his feelings known about a model of a bridge designed by Anna's engineer boyfriend by smashing it before the judges of a competition have weighed in. By this point, he's developed a fondness for his assistant, and his outburst clearly is driven by jealousy.

A stickler for authenticity, Harris learned to write music in Beethoven's style of handwriting -- those are the actor's hands scrawling the end of the maestro's famed symphony -- and to conduct more than passably. That's really him leading Hungary's Kecskemet Symphony Orchestra in the Ninth on the beat, his hair bobbing up and down in rhythm.

But Harris' impressive channeling of Ludwig is diluted by the decision of screenwriters Stephen Rivele and Christopher Wilkinson to put the copyist front and center, possibly to distinguish their feature from "Immortal Beloved." They've ended up composing the equivalent of a discordant movement in which Anna's ambition to become a composer like her employer is continually hampered by her gender. To introduce the notion of feminism in a movie set in 19th century Vienna (Budapest makes a convincing stand-in) seems kind of silly, especially when it's so obviously filtered through a 21st century sensibility. (The maestro's real-life copyists were men, but it wouldn't do at all to show him flirting with one of them.)

"Copying Beethoven" might have worked even with the feminism angle if Kruger were a more inventive actress. Anna should have been played as a bundle of unbridled ambition, a prototype for Eve Harrington, flattering Ludwig while plotting to make her move, using his fame to advance her career.

But Kruger is all sweetness and light, giving no indication of the complexity necessary for Anna to be interesting enough to devote half a movie to. Kruger appears to be making a habit of failing to make an impression. Remember her in "Troy" or "Joyeux Noel?" Me neither.